Rain Shaft/Shelf Cloud

Rain-Free Base
Rain Free Base
-Forms from updraft which keeps all precipitation suspended
-If looking at the rain-free base, the wind should be at your back
-Look here for possible wall cloud development
-"Scattered Cumulus Under Deck"
-These are very low level clouds below the rain-free base
-Often confused as funnel clouds
-Lack rotation and are disconnected with main cloud base
Wall Cloud
Wall Cloud
-Lowering from the rain-free base
-Occur due to influx of moist air which lowers the dewpoint depression, and in turn, the cloud base (LCL).
-"Most tornadoes form from wall clouds, but most wall clouds don't form tornadoes"
-Look for rotation as a good precursor to possible tornado formation.
Funnel Cloud
Funnel Cloud
-Funnel clouds can extend downward from a rotating wall cloud.
-Violently rotating column of air extending from the base of a thunderstorm as a condensation funnel.
-NOT in contact with the ground.
-Watch as funnel extends to ground or debris cloud forms which would make it a tornado.
-Violently rotating column of air extending from the base of a thunderstorm in contact with the ground.
-Look for debris cloud or condensation funnel extending from wall cloud to the ground.
-Strength based on Enhanced Fujita Scale (damaged based scale).
-Tornadoes should be reported to the local weather service office or by dialing 911.
-Extreme caution should be used when observing tornadoes (they can move at very fast speeds and change directions quickly)

Shelf Cloud
Shelf Cloud
-Shelf clouds usually represent the leading edge of the gust fronts
-Very fast straight-line winds associated with shelf cloud
-Identifiable as long, skinny cloud lowered from the main base of the storm
-Differentiated from wall clouds because when looking at a shelf cloud, wind will be in your face.

Hail Shaft
Hail Shaft
-Differentiated from rain shafts by their off-white/greyish coloration.
-Large hail (up to the size of softballs) common in the Great Plains.
-Largest hail often on the updraft/downdraft border.
-While chasing, hail shafts should be avoided (can hide deadly tornadoes, dent cars, and destroy windshields).
Rain Shaft
Rain Shaft
-Rain shafts have a dark grey/bluish tint as opposed to hail shafts.
-The danger in rain shafts come from the flooding potential ("Turn around don't drown") and their shielding visibility of potentially more dangerous parts of a storm.

-Gustnadoes are not technically tornadoes because they are not in contact with the main cloud base.
-Gustnadoes are weaker than most wall cloud based tornadoes but can still cause minor damage (especially to cars).
-Gustnadoes can be easily differentiated from tornadoes because they occur in teh outflow part of a storm; often under the shelf cloud. 

Mammatus Clouds
Mammatus Clouds
-Mammatus clouds form from the sinking of moist air into drier air.
-Think of them as an upside down cloud.
-Not necessarily structurally significant but often provide breathtaking sights and pictures.
Towering Cumulus Clouds
Towering Cumulus
-Cumulus clouds with significant vertical development.
-Often aller than they are wide.
-Good sign of instability and potential storm development
-Become Cumulonimbus clouds when rain begins to fall.
-Can form in lines along fronts or as isolated clouds (these are often the ones to chase as they will solely use all of the available moisture and energy)
-Gets name from the anvil shape (larger on top than on the bottom).
-Represents teh top of a thunderstorm.
-Not all storms possess anvil clouds.
-Can be seen from over 50 miles away if terrain permits.
-Tops of anvils often 40,000 feet high.